Like its cousin, the Golden-crowned Kinglet (see The Daily World, 4/15/2012), the Ruby-crowned Kinglet is a very tiny bird with a very high-energy lifestyle, constantly in motion, though not as acrobatic as the Golden-crowned. While the Golden-crowned hangs upside down at the end of a cone or leaf to find the insects, the Ruby-crowned is more likely to hover as it feeds under the leaf or at the end of the cones, using more energy. They belong to the same “guild” of birds, those that are similar in shape and size and “exploit the same set of resources in a similar manner”, according to “The Birder’s Handbook; a Field Guide to the Natural History of North American Birds”, by Ehrlich, Dobkin & Wheye. This guild includes the Hutton’s Vireo, the bird most similar-looking to the RCKI, yet each of these birds differ in their food requirements just enough to prevent real competition for the available resources. Here are some of the things you need to know about this bird.
Size: 4.25 inches from head to tail, wing span is 7.5 inches, and weight is 0.23 ounces.
General Description: An olive-green to gray songbird, with dark wings and two white, diagonal wing-bars. Beneath the lower, brighter wing-bar is a black patch at the base of the secondaries which helps distinguish the Ruby-crowned from the similar-appearing Hutton’s Vireo. They have a dark eye surrounded by a white eye-ring, a short bill, black legs and yellow feet. They are just a bit larger than the Golden-crowned, and lack the brightly striped head of their cousin. The male Ruby-crowned has a red to red-orange crest that is only seen when the bird is excited. Females resemble the males but lack the red crest.
Habitat: Ruby-crowned are common in openings of heavily wooded areas, particularly in spruce and fir, or in wetlands within the forest zones. In the winter and during migration they prefer the lowland forest and shrub habitat. They nest high in trees, so prefer older, taller and denser stands of timber.
Behavior: These birds mix with others of their guild in feeding flocks, moving rapidly up and down the brush and tree limbs, hovering to get to the underside of the leaves and twigs, usually at lower levels than the others in the group. They also are notable for the constant flicking of their wings.
Diet: Ruby-crowned eat small insects such as aphids, wasps, ants, spiders, bark beetles, and the eggs of insects stuck to the underside of leaves and twigs. In winter they also eat some seeds, sap, and berries.
Nesting: Ruby-crowned Kinglets are monogamous but only for each breeding season, forming new pair-bonds each year. Their nests are usually 40 to 100 feet off the ground and woven into a teardrop-shaped basket, looking as though it had been knitted from dried grasses, moss and spiderweb. It takes the female five days to build the nest, which is actually made of grasses, feathers, mosses, spiderwebs and cocoon silk. It is lined with fine plant down, feathers, and fur, suspended from two twigs, and measures approximately 4 inches wide and 5 to 6 inches deep. It is elastic enough it can stretch to hold a large and growing brood and needs a lot of maintenance to keep it from disintegrating. Clutches in the Pacific Northwest typically range from 9 to 12 eggs, with incubation lasting about two weeks. The male feeds the female during this time and for the brooding period of a few more days, then the female joins the male in bringing food to the young. The young leave the nest about 16 days after hatching while the male continues to feed them for another 10 days, but the female may leave the breeding territory. Because their nests are so high in the trees and often in remote locations, some of the information is sketchy. It is thought Ruby-crowned raise just one brood a year.
Migration Status: Ruby-crowned Kinglet migration is determined by temperature, so they migrate earlier in the fall and later in the spring than Golden-crowned Kinglets. They are less well-adapted to cold, so winter farther south than the Golden-crowned, across the southern states, into Mexico, and as far south as western Central America.
Conservation Status: Ruby-crowned Kinglets are widespread and common throughout North America, and their population fluctuates with colder winters when they experience winter die-offs. They have proven to be fairly tolerant of man-made changes in the landscape, but logging and wildfires have shrunk their breeding range.
When and Where to Find in Grays Harbor: Ruby-crowned Kinglets are common in winter in the lowlands all the way out to the coast, and they breed in the Olympics. In order to see them, you have to stand still in an area of trees and be ready to experience what is called “warbler neck” by those in the know. It is the pain experienced by standing with one’s head back for extended periods of time. A good place to try this is out on the Sandpiper Trail at the Grays Harbor National Wildlife Refuge, in the large treed area within the circle of the boardwalk, or perhaps the trails at Lake Swano on the campus of Grays Harbor College. I am sure they can also be seen at Lake Sylvia. But you have to be sharp, they move very fast.